From: Christoffer Dall <christoffer.dall@linaro.org>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andrew Jones <drjones@redhat.com>,
linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH v2 17/17] arm64: KVM: vgic-v3: Do not save ICH_AP0Rn_EL2 for GICv2 emulation
Date: Thu, 3 Mar 2016 20:21:54 +0100 [thread overview]
Message-ID: <20160303192154.GJ9634@cbox> (raw)
In-Reply-To: <1455727249-24752-18-git-send-email-marc.zyngier@arm.com>
On Wed, Feb 17, 2016 at 04:40:49PM +0000, Marc Zyngier wrote:
> The GICv3 specification mandates that ICH_AP0Rn_EL2 are set to
> zero when running guests that use the memory mapped registers.
>
> This is fine, as we initialize all ICH_AP0Rn_EL2 registers to
> zero, and restore them on entry. But it also means that we
> do not need to save these registers on exit. Profit!
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> arch/arm64/kvm/hyp/vgic-v3-sr.c | 19 +++++++++++--------
> 1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
> index 5f12c57..c2f173d 100644
> --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
> +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
> @@ -202,14 +202,17 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
> __gic_v3_set_lr(0, i);
> }
>
> - switch (nr_pri_bits) {
> - case 7:
> - cpu_if->vgic_ap0r[3] = read_gicreg(ICH_AP0R3_EL2);
> - cpu_if->vgic_ap0r[2] = read_gicreg(ICH_AP0R2_EL2);
> - case 6:
> - cpu_if->vgic_ap0r[1] = read_gicreg(ICH_AP0R1_EL2);
> - default:
> - cpu_if->vgic_ap0r[0] = read_gicreg(ICH_AP0R0_EL2);
> + /* ICH_AP0Rn is only valid for SRE==1 */
> + if (cpu_if->vgic_sre & ICC_SRE_EL1_SRE) {
> + switch (nr_pri_bits) {
> + case 7:
> + cpu_if->vgic_ap0r[3] = read_gicreg(ICH_AP0R3_EL2);
> + cpu_if->vgic_ap0r[2] = read_gicreg(ICH_AP0R2_EL2);
> + case 6:
> + cpu_if->vgic_ap0r[1] = read_gicreg(ICH_AP0R1_EL2);
> + default:
> + cpu_if->vgic_ap0r[0] = read_gicreg(ICH_AP0R0_EL2);
> + }
> }
>
> switch (nr_pri_bits) {
> --
> 2.1.4
>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
next prev parent reply other threads:[~2016-03-03 19:21 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-17 16:40 [PATCH v2 00/17] KVM/ARM: Guest Entry/Exit optimizations Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 01/17] arm64: KVM: Switch the sys_reg search to be a binary search Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 02/17] ARM: KVM: Properly sort the invariant table Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 03/17] ARM: KVM: Enforce sorting of all CP tables Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 04/17] ARM: KVM: Rename struct coproc_reg::is_64 to is_64bit Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 05/17] ARM: KVM: Switch the CP reg search to be a binary search Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 06/17] KVM: arm/arm64: timer: Add active state caching Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 07/17] arm64: KVM: vgic-v2: Avoid accessing GICH registers Marc Zyngier
2016-03-02 23:08 ` Christoffer Dall
2016-02-17 16:40 ` [PATCH v2 08/17] arm64: KVM: vgic-v2: Save maintenance interrupt state only if required Marc Zyngier
2016-03-02 23:08 ` Christoffer Dall
2016-03-03 8:28 ` Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 09/17] arm64: KVM: vgic-v2: Move GICH_ELRSR saving to its own function Marc Zyngier
2016-03-02 23:08 ` Christoffer Dall
2016-02-17 16:40 ` [PATCH v2 10/17] arm64: KVM: vgic-v2: Do not save an LR known to be empty Marc Zyngier
2016-03-02 23:08 ` Christoffer Dall
2016-02-17 16:40 ` [PATCH v2 11/17] arm64: KVM: vgic-v2: Only wipe LRs on vcpu exit Marc Zyngier
2016-03-02 23:08 ` Christoffer Dall
2016-03-03 8:14 ` Marc Zyngier
2016-03-03 15:58 ` Marc Zyngier
2016-03-04 11:36 ` Christoffer Dall
2016-03-04 11:45 ` Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 12/17] arm64: KVM: vgic-v2: Make GICD_SGIR quicker to hit Marc Zyngier
2016-03-02 23:08 ` Christoffer Dall
2016-02-17 16:40 ` [PATCH v2 13/17] arm64: KVM: vgic-v3: Avoid accessing ICH registers Marc Zyngier
2016-02-17 16:40 ` [PATCH v2 14/17] arm64: KVM: vgic-v3: Save maintenance interrupt state only if required Marc Zyngier
2016-03-03 19:21 ` Christoffer Dall
2016-02-17 16:40 ` [PATCH v2 15/17] arm64: KVM: vgic-v3: Do not save an LR known to be empty Marc Zyngier
2016-03-03 19:21 ` Christoffer Dall
2016-02-17 16:40 ` [PATCH v2 16/17] arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit Marc Zyngier
2016-03-03 19:21 ` Christoffer Dall
2016-02-17 16:40 ` [PATCH v2 17/17] arm64: KVM: vgic-v3: Do not save ICH_AP0Rn_EL2 for GICv2 emulation Marc Zyngier
2016-03-03 19:21 ` Christoffer Dall [this message]
2016-03-04 8:54 ` Marc Zyngier
2016-02-29 0:57 ` [PATCH v2 00/17] KVM/ARM: Guest Entry/Exit optimizations Mihai Claudiu Caraman
2016-02-29 8:26 ` Marc Zyngier
2016-02-29 10:43 ` Mihai Claudiu Caraman
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